Bear Lake, one of the few natural lakes in Utah, possesses two interesting features: at least four endemic fish species live here, and many of the fishes in the lake use benthic invertegrates as a primary food source. Because of these features, Bear Lake provides an opportunity where relationships between parasites and their hosts can be studies in a community with a history of isolation and minimal external influences. Specific questions addressed in this study are: 1) Are fish helminth communities in Bear Lake stochastic, depauperate, and non-interactive or are they structured assemblages and interactive? And 2) Does the oligotrophic status of Bear Lake result in a parasite food web that is dominated by autogenic parasite species (species which use fish in the lake as both an intermediate and definitive host)? Parameters to quantify structure of helminth assemblages in Bear Lake fish include: prevalence, a diversity index, a dominance index, both qualitative and quantitative similarity indices, and site location of gastrointestinal helminths. A food web for Bear Lake parasites will be developed incorporating the interactions between fish definitive hosts, fish/benthic invertebrate intermediate hosts, and parasite infra- and component communities. Minority students involved in this project will study a natural host-parasite system. They will become knowledgeable and skillful in parasite ecology and learn fundamental aspects of interactions between parasites and their hosts that are applicable to most host- parasite systems including human host-parasite systems. Exposure to parasite ecological concepts will be especially useful to students that enter a biomedical field that involves studying the epidemiology of parasitic diseases of humans.